1. Field of the Invention
The invention relates to the field of shifting systems for automatic transmissions and, in particular, to a steering wheel mounted shifting system suitable for after-market instillation.
2. Description of Related Art
Originally all transmission shifting was accomplished manually with a stick type shifter positioned on the floor. However, this made three abreast seating in the front seat of the automobile difficult. To provide for three abreast seating in the front seat, column-mounted manual shifting systems became popular. This mounting position remained popular even when automatic transmissions were introduced. However, sport cars and most racing cars still used floor-mounted shifters. Chrysler Corporation in the 1950's time frame introduced a push button controlled transmission located in the center of the steering wheel hub. However, it proved to have a short life and the column mounted shift lever remained the standard.
When the sport or sporty car became popular, the trend reverted back to mounting the shifter on the floor, in reality on top of the transmission. In fact, with the advent of “bucket seats” limiting the front of the passenger compartment to two, center mounting the shifter was a significant cost saver. However, more recent advancements, particularly in Formula One racing cars, have produced automatic shifting manual transmissions. That is by use of electronics and hydraulic or electric actuators, a manual type transmission with clutch that can be automatically shifted. This advancement led to the placement of the shifting mechanism back on to the steering column, where paddles and the like accomplish shifting. Presently, this concept is being introduced into production automobiles. In fact, it is being used in conjunction with automatic transmissions on cars manufactured by Porsche and the Pontiac Division of General Motors. Many other manufactures are expected to follow with such shifting systems.
Thus there is a need for after-market conversion kits to convert floor mounted and column mounted shifting systems to a steering wheel-mounted system. A system to convert manual transmissions with a floor-mounted shifter is disclosed in U.S. Pat. No. 4,960,008 Automotive Transmission Linkage System. Here an electromechanical actuator system is connected to gearshift lever of a manual transmission. The actuator system is connected to a push button shifting control device mounted on the steering column. This after market device, while designed for a manual transmission does perform the function of gear selection.
However, this system does not address several of the major problems of after-market installation. First of all, it is important that the system be easily installed on a wide variety of automobiles. In addition, the existing wiring systems within the automobile must not be unduly affected, lest the product be too costly to install. It must also meet all existing safety requirements. For example, shifting out of the park position can not be accomplished unless the break pedal is depressed. It must not affect airbag performance in any way.
Thus, it is a primary object of the invention to provide a transmission shifting system that converts a floor mounted and column mounted shifting system to a steering wheel mounted system for after-market installation on automobiles with automatic transmissions.
It is another primary object of the invention to provide a transmission shifting system that converts a floor mounted and column mounted shifting system to a steering wheel mounted system for after-market installation on automobiles with automatic transmissions that does not require extensive modification to the wiring system of the automobile.
It is a further object of the invention to provide a transmission shifting system that converts a floor mounted and column mounted shifting system to a steering wheel mounted system for after-market installation on a wide variety of automobiles with automatic transmissions.